1
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Bauer MS, Gruber S, Hausch A, Melo MCR, Gomes PSFC, Nicolaus T, Milles LF, Gaub HE, Bernardi RC, Lipfert J. Single-molecule force stability of the SARS-CoV-2-ACE2 interface in variants-of-concern. NATURE NANOTECHNOLOGY 2024; 19:399-405. [PMID: 38012274 DOI: 10.1038/s41565-023-01536-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 09/26/2023] [Indexed: 11/29/2023]
Abstract
Mutations in SARS-CoV-2 have shown effective evasion of population immunity and increased affinity to the cellular receptor angiotensin-converting enzyme 2 (ACE2). However, in the dynamic environment of the respiratory tract, forces act on the binding partners, which raises the question of whether not only affinity but also force stability of the SARS-CoV-2-ACE2 interaction might be a selection factor for mutations. Using magnetic tweezers, we investigate the impact of amino acid substitutions in variants of concern (Alpha, Beta, Gamma and Delta) and on force-stability and bond kinetic of the receptor-binding domain-ACE2 interface at a single-molecule resolution. We find a higher affinity for all of the variants of concern (>fivefold) compared with the wild type. In contrast, Alpha is the only variant of concern that shows higher force stability (by 17%) compared with the wild type. Using molecular dynamics simulations, we rationalize the mechanistic molecular origins of this increase in force stability. Our study emphasizes the diversity of contributions to the transmissibility of variants and establishes force stability as one of the several factors for fitness. Understanding fitness advantages opens the possibility for the prediction of probable mutations, allowing a rapid adjustment of therapeutics, vaccines and intervention measures.
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Affiliation(s)
- Magnus S Bauer
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
- Department of Chemical Engineering, Stanford University, Stanford, CA, USA
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Sophia Gruber
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
| | - Adina Hausch
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
- Center for Protein Assemblies, TUM School of Natural Sciences, Technical University of Munich, Munich, Germany
| | | | | | - Thomas Nicolaus
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
| | - Lukas F Milles
- Department of Biochemistry, University of Washington, Seattle, WA, USA
- Institute for Protein Design, University of Washington, Seattle, WA, USA
| | - Hermann E Gaub
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany
| | | | - Jan Lipfert
- Department of Physics and Center for NanoScience (CeNS), LMU Munich, Munich, Germany.
- Department of Physics and Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, The Netherlands.
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2
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Mierke CT. Magnetic tweezers in cell mechanics. Methods Enzymol 2024; 694:321-354. [PMID: 38492957 DOI: 10.1016/bs.mie.2023.12.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
The chapter provides an overview of the applications of magnetic tweezers in living cells. It discusses the advantages and disadvantages of magnetic tweezers technology with a focus on individual magnetic tweezers configurations, such as electromagnetic tweezers. Solutions to the disadvantages identified are also outlined. The specific role of magnetic tweezers in the field of mechanobiology, such as mechanosensitivity, mechano-allostery and mechanotransduction are also emphasized. The specific usage of magnetic tweezers in mechanically probing cells via specific cell surface receptors, such as mechanosensitive channels is discussed and why mechanical probing has revealed the opening and closing of the channels. Finally, the future direction of magnetic tweezers is presented.
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Affiliation(s)
- Claudia Tanja Mierke
- Faculty of Physics and Earth System Sciences, Peter Debye Institute for Soft Matter Physics, Biological Physics Division, Leipzig University, Leipzig, Germany.
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3
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Dulin D. An Introduction to Magnetic Tweezers. Methods Mol Biol 2024; 2694:375-401. [PMID: 37824014 DOI: 10.1007/978-1-0716-3377-9_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
Magnetic tweezers are a single-molecule force and torque spectroscopy technique that enable the mechanical interrogation in vitro of biomolecules, such as nucleic acids and proteins. They use a magnetic field originating from either permanent magnets or electromagnets to attract a magnetic particle, thus stretching the tethering biomolecule. They nicely complement other force spectroscopy techniques such as optical tweezers and atomic force microscopy (AFM) as they operate as a very stable force clamp, enabling long-duration experiments over a very broad range of forces spanning from 10 fN to 1 nN, with 1-10 milliseconds time and sub-nanometer spatial resolution. Their simplicity, robustness, and versatility have made magnetic tweezers a key technique within the field of single-molecule biophysics, being broadly applied to study the mechanical properties of, e.g., nucleic acids, genome processing molecular motors, protein folding, and nucleoprotein filaments. Furthermore, magnetic tweezers allow for high-throughput single-molecule measurements by tracking hundreds of biomolecules simultaneously both in real-time and at high spatiotemporal resolution. Magnetic tweezers naturally combine with surface-based fluorescence spectroscopy techniques, such as total internal reflection fluorescence microscopy, enabling correlative fluorescence and force/torque spectroscopy on biomolecules. This chapter presents an introduction to magnetic tweezers including a description of the hardware, the theory behind force calibration, its spatiotemporal resolution, combining it with other techniques, and a (non-exhaustive) overview of biological applications.
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Affiliation(s)
- David Dulin
- LaserLaB Amsterdam and Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
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4
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He T, Fisher GJ, Kim AJ, Quan T. Age-related changes in dermal collagen physical properties in human skin. PLoS One 2023; 18:e0292791. [PMID: 38064445 PMCID: PMC10707495 DOI: 10.1371/journal.pone.0292791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 09/28/2023] [Indexed: 12/18/2023] Open
Abstract
Collagen is the major structural protein in the skin. Fragmentation and disorganization of the collagen fibrils are the hallmarks of the aged human skin dermis. These age-related alterations of collagen fibrils impair skin structural integrity and make the tissue microenvironment more prone to skin disorders. As the biological function of collagen lies predominantly in its physical properties, we applied atomic force microscopy (AFM) and nanoindentation to evaluate the physical properties (surface roughness, stiffness, and hardness) of dermal collagen in young (25±5 years, N = 6) and aged (75±6 years, N = 6) healthy sun-protected hip skin. We observed that in the aged dermis, the surface of collagen fibrils was rougher, and fiber bundles were stiffer and harder, compared to young dermal collagen. Mechanistically, the age-related elevation of matrix metalloproteinase-1 (MMP-1) and advanced glycation end products (AGEs) are responsible for rougher and stiffer/harder dermal collagen, respectively. Analyzing the physical properties of dermal collagen as a function of age revealed that alterations of the physical properties of collagen fibrils changed with age (22-89 years, N = 18). We also observed that the reticular dermis is rougher and mechanically stiffer and harder compared to the papillary dermis in human skin. These data extend the current understanding of collagen beyond biological entities to include biophysical properties.
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Affiliation(s)
- Tianyuan He
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Gary J. Fisher
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ava J. Kim
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Taihao Quan
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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5
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Svirelis J, Adali Z, Emilsson G, Medin J, Andersson J, Vattikunta R, Hulander M, Järlebark J, Kolman K, Olsson O, Sakiyama Y, Lim RYH, Dahlin A. Stable trapping of multiple proteins at physiological conditions using nanoscale chambers with macromolecular gates. Nat Commun 2023; 14:5131. [PMID: 37612271 PMCID: PMC10447545 DOI: 10.1038/s41467-023-40889-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 08/11/2023] [Indexed: 08/25/2023] Open
Abstract
The possibility to detect and analyze single or few biological molecules is very important for understanding interactions and reaction mechanisms. Ideally, the molecules should be confined to a nanoscale volume so that the observation time by optical methods can be extended. However, it has proven difficult to develop reliable, non-invasive trapping techniques for biomolecules under physiological conditions. Here we present a platform for long-term tether-free (solution phase) trapping of proteins without exposing them to any field gradient forces. We show that a responsive polymer brush can make solid state nanopores switch between a fully open and a fully closed state with respect to proteins, while always allowing the passage of solvent, ions and small molecules. This makes it possible to trap a very high number of proteins (500-1000) inside nanoscale chambers as small as one attoliter, reaching concentrations up to 60 gL-1. Our method is fully compatible with parallelization by imaging arrays of nanochambers. Additionally, we show that enzymatic cascade reactions can be performed with multiple native enzymes under full nanoscale confinement and steady supply of reactants. This platform will greatly extend the possibilities to optically analyze interactions involving multiple proteins, such as the dynamics of oligomerization events.
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Affiliation(s)
- Justas Svirelis
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Zeynep Adali
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Gustav Emilsson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Jesper Medin
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - John Andersson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Radhika Vattikunta
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Mats Hulander
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Julia Järlebark
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Krzysztof Kolman
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Oliver Olsson
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden
| | - Yusuke Sakiyama
- Biozentrum and the Swiss Nanoscience Institute, University of Basel, 4056, Basel, Switzerland
| | - Roderick Y H Lim
- Biozentrum and the Swiss Nanoscience Institute, University of Basel, 4056, Basel, Switzerland
| | - Andreas Dahlin
- Department of Chemistry and Chemical Engineering, Chalmers University of Technology, 41296, Gothenburg, Sweden.
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6
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Cai X, Xu L. A Piezoelectrically Excited ZnO Nanowire Mass Sensor with Closed-Loop Detection at Room Temperature. MICROMACHINES 2022; 13:2242. [PMID: 36557541 PMCID: PMC9788434 DOI: 10.3390/mi13122242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/14/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
One-dimensional nanobeam mass sensors offer an unprecedented ability to measure tiny masses or even the mass of individual molecules or atoms, enabling many interesting applications in the fields of mass spectrometry and atomic physics. However, current nano-beam mass sensors suffer from poor real-time test performance and high environment requirements. This paper proposes a piezoelectrically excited ZnO nanowire (NW) mass sensor with closed-loop detection at room temperature to break this limitation. It is detected that the designed piezo-excited ZnO NW could operate at room temperature with a resonant frequency of 417.35 MHz, a quality factor of 3010, a mass sensitivity of -8.1 Hz/zg, and a resolution of 192 zg. The multi-field coupling dynamic model of ZnO NW mass sensor under piezoelectric excitation was established and solved. The nonlinear amplitude-frequency characteristic formula, frequency formula, modal function, sensitivity curve, and linear operating interval were obtained. The ZnO NW mass sensor was fabricated by a top-down method and its response to ethanol gas molecules was tested at room temperature. Experiments show that the sensor has high sensitivity, good closed-loop tracking performance, and high linearity, which provides great potential for the detection of biochemical reaction process of biological particles based on mechanics.
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7
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Huisjes NM, Retzer TM, Scherr MJ, Agarwal R, Rajappa L, Safaric B, Minnen A, Duderstadt KE. Mars, a molecule archive suite for reproducible analysis and reporting of single-molecule properties from bioimages. eLife 2022; 11:75899. [PMID: 36098381 PMCID: PMC9470159 DOI: 10.7554/elife.75899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 08/19/2022] [Indexed: 11/16/2022] Open
Abstract
The rapid development of new imaging approaches is generating larger and more complex datasets, revealing the time evolution of individual cells and biomolecules. Single-molecule techniques, in particular, provide access to rare intermediates in complex, multistage molecular pathways. However, few standards exist for processing these information-rich datasets, posing challenges for wider dissemination. Here, we present Mars, an open-source platform for storing and processing image-derived properties of biomolecules. Mars provides Fiji/ImageJ2 commands written in Java for common single-molecule analysis tasks using a Molecule Archive architecture that is easily adapted to complex, multistep analysis workflows. Three diverse workflows involving molecule tracking, multichannel fluorescence imaging, and force spectroscopy, demonstrate the range of analysis applications. A comprehensive graphical user interface written in JavaFX enhances biomolecule feature exploration by providing charting, tagging, region highlighting, scriptable dashboards, and interactive image views. The interoperability of ImageJ2 ensures Molecule Archives can easily be opened in multiple environments, including those written in Python using PyImageJ, for interactive scripting and visualization. Mars provides a flexible solution for reproducible analysis of image-derived properties, facilitating the discovery and quantitative classification of new biological phenomena with an open data format accessible to everyone.
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Affiliation(s)
- Nadia M Huisjes
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Thomas M Retzer
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany.,Physik Department, Technische Universität München, Garching, Germany
| | - Matthias J Scherr
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Rohit Agarwal
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany.,Physik Department, Technische Universität München, Garching, Germany
| | - Lional Rajappa
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Barbara Safaric
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Anita Minnen
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Karl E Duderstadt
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany.,Physik Department, Technische Universität München, Garching, Germany
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8
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Rahman M, Islam KR, Islam MR, Islam MJ, Kaysir MR, Akter M, Rahman MA, Alam SMM. A Critical Review on the Sensing, Control, and Manipulation of Single Molecules on Optofluidic Devices. MICROMACHINES 2022; 13:968. [PMID: 35744582 PMCID: PMC9229244 DOI: 10.3390/mi13060968] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/19/2022] [Accepted: 05/23/2022] [Indexed: 02/06/2023]
Abstract
Single-molecule techniques have shifted the paradigm of biological measurements from ensemble measurements to probing individual molecules and propelled a rapid revolution in related fields. Compared to ensemble measurements of biomolecules, single-molecule techniques provide a breadth of information with a high spatial and temporal resolution at the molecular level. Usually, optical and electrical methods are two commonly employed methods for probing single molecules, and some platforms even offer the integration of these two methods such as optofluidics. The recent spark in technological advancement and the tremendous leap in fabrication techniques, microfluidics, and integrated optofluidics are paving the way toward low cost, chip-scale, portable, and point-of-care diagnostic and single-molecule analysis tools. This review provides the fundamentals and overview of commonly employed single-molecule methods including optical methods, electrical methods, force-based methods, combinatorial integrated methods, etc. In most single-molecule experiments, the ability to manipulate and exercise precise control over individual molecules plays a vital role, which sometimes defines the capabilities and limits of the operation. This review discusses different manipulation techniques including sorting and trapping individual particles. An insight into the control of single molecules is provided that mainly discusses the recent development of electrical control over single molecules. Overall, this review is designed to provide the fundamentals and recent advancements in different single-molecule techniques and their applications, with a special focus on the detection, manipulation, and control of single molecules on chip-scale devices.
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Affiliation(s)
- Mahmudur Rahman
- Department of Electrical and Electronic Engineering, Dhaka University of Engineering & Technology, Gazipur 1707, Bangladesh; (M.R.); (K.R.I.); (M.R.I.); (M.A.); (M.A.R.)
| | - Kazi Rafiqul Islam
- Department of Electrical and Electronic Engineering, Dhaka University of Engineering & Technology, Gazipur 1707, Bangladesh; (M.R.); (K.R.I.); (M.R.I.); (M.A.); (M.A.R.)
| | - Md. Rashedul Islam
- Department of Electrical and Electronic Engineering, Dhaka University of Engineering & Technology, Gazipur 1707, Bangladesh; (M.R.); (K.R.I.); (M.R.I.); (M.A.); (M.A.R.)
| | - Md. Jahirul Islam
- Department of Electrical and Electronic Engineering, Khulna University of Engineering & Technology, Khulna 9203, Bangladesh;
| | - Md. Rejvi Kaysir
- Department of Electrical and Computer Engineering, University of Waterloo, 200 University Ave. W, Waterloo, ON N2L 3G1, Canada;
- Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave. W, Waterloo, ON N2L 3G1, Canada
| | - Masuma Akter
- Department of Electrical and Electronic Engineering, Dhaka University of Engineering & Technology, Gazipur 1707, Bangladesh; (M.R.); (K.R.I.); (M.R.I.); (M.A.); (M.A.R.)
| | - Md. Arifur Rahman
- Department of Electrical and Electronic Engineering, Dhaka University of Engineering & Technology, Gazipur 1707, Bangladesh; (M.R.); (K.R.I.); (M.R.I.); (M.A.); (M.A.R.)
| | - S. M. Mahfuz Alam
- Department of Electrical and Electronic Engineering, Dhaka University of Engineering & Technology, Gazipur 1707, Bangladesh; (M.R.); (K.R.I.); (M.R.I.); (M.A.); (M.A.R.)
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9
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Aicart-Ramos C, Hormeno S, Wilkinson OJ, Dillingham MS, Moreno-Herrero F. Long DNA constructs to study helicases and nucleic acid translocases using optical tweezers. Methods Enzymol 2022; 673:311-358. [DOI: 10.1016/bs.mie.2022.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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10
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Salerno D, Marrano CA, Cassina V, Cristofalo M, Shao Q, Finzi L, Mantegazza F, Dunlap D. Nanomechanics of negatively supercoiled diaminopurine-substituted DNA. Nucleic Acids Res 2021; 49:11778-11786. [PMID: 34718727 PMCID: PMC8599871 DOI: 10.1093/nar/gkab982] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 11/25/2022] Open
Abstract
Single molecule experiments have demonstrated a progressive transition from a B- to an L-form helix as DNA is gently stretched and progressively unwound. The particular sequence of a DNA segment defines both base stacking and hydrogen bonding that affect the partitioning and conformations of the two phases. Naturally or artificially modified bases alter H-bonds and base stacking and DNA with diaminopurine (DAP) replacing adenine was synthesized to produce linear fragments with triply hydrogen-bonded DAP:T base pairs. Both unmodified and DAP-substituted DNA transitioned from a B- to an L-helix under physiological conditions of mild tension and unwinding. This transition avoids writhing and the ease of this transition may prevent cumbersome topological rearrangements in genomic DNA that would require topoisomerase activity to resolve. L-DNA displayed about tenfold lower persistence length than B-DNA. However, left-handed DAP-substituted DNA was twice as stiff as unmodified L-DNA. Unmodified DNA and DAP-substituted DNA have very distinct mechanical characteristics at physiological levels of negative supercoiling and tension.
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Affiliation(s)
- Domenico Salerno
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, Università di Milano-Bicocca, via R. Follereau 3, Vedano al Lambro (MB), Italy
| | - Claudia Adriana Marrano
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, Università di Milano-Bicocca, via R. Follereau 3, Vedano al Lambro (MB), Italy
| | - Valeria Cassina
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, Università di Milano-Bicocca, via R. Follereau 3, Vedano al Lambro (MB), Italy
| | - Matteo Cristofalo
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, Università di Milano-Bicocca, via R. Follereau 3, Vedano al Lambro (MB), Italy
| | - Qing Shao
- Department of Physics, Emory University, Atlanta, GA USA
| | - Laura Finzi
- Department of Physics, Emory University, Atlanta, GA USA
| | - Francesco Mantegazza
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, Università di Milano-Bicocca, via R. Follereau 3, Vedano al Lambro (MB), Italy
| | - David Dunlap
- Department of Physics, Emory University, Atlanta, GA USA
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11
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Bocanegra R, Plaza G A I, Ibarra B. In vitro single-molecule manipulation studies of viral DNA replication. Enzymes 2021; 49:115-148. [PMID: 34696830 DOI: 10.1016/bs.enz.2021.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Faithfull replication of genomic information relies on the coordinated activity of the multi-protein machinery known as the replisome. Several constituents of the replisome operate as molecular motors that couple thermal and chemical energy to a mechanical task. Over the last few decades, in vitro single-molecule manipulation techniques have been used to monitor and manipulate mechanically the activities of individual molecular motors involved in DNA replication with nanometer, millisecond, and picoNewton resolutions. These studies have uncovered the real-time kinetics of operation of these biological systems, the nature of their transient intermediates, and the processes by which they convert energy to work (mechano-chemistry), ultimately providing new insights into their inner workings of operation not accessible by ensemble assays. In this chapter, we describe two of the most widely used single-molecule manipulation techniques for the study of DNA replication, optical and magnetic tweezers, and their application in the study of the activities of proteins involved in viral DNA replication.
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Affiliation(s)
- Rebeca Bocanegra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain
| | - Ismael Plaza G A
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, Madrid, Spain.
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12
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Liu W, Li J, Xu Y, Yin D, Zhu X, Fu H, Su X, Guo X. Complete Mapping of DNA‐Protein Interactions at the Single‐Molecule Level. ADVANCED SCIENCE 2021; 8:2101383. [PMCID: PMC8655176 DOI: 10.1002/advs.202101383] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
DNA–protein interaction plays an essential role in the storage, expression, and regulation of genetic information. A 1D/3D facilitated diffusion mechanism has been proposed to explain the extraordinarily rapid rate of DNA‐binding protein (DBP) searching for cognate sequence along DNA and further studied by single‐molecule experiments. However, direct observation of the detailed chronological protein searching image is still a formidable challenge. Here, for the first time, a single‐molecule electrical monitoring technique is utilized to realize label‐free detection of the DBP–DNA interaction process based on high‐gain silicon nanowire field‐effect transistors (SiNW FETs). The whole binding process of WRKY domain and DNA has been visualized with high sensitivity and single‐base resolution. Impressively, the swinging of hydrogen bonds between amino acid residues and bases in DNA induce the dynamic collective motion of DBP–DNA. This in situ, label‐free electrical detection platform provides a practical experimental methodology for dynamic studies of various biomolecules.
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Affiliation(s)
- Wenzhe Liu
- State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesBeijing National Laboratory for Molecular SciencesNational Biomedical Imaging CenterCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871P. R. China
| | - Jie Li
- State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesBeijing National Laboratory for Molecular SciencesNational Biomedical Imaging CenterCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871P. R. China
- Shenzhen Bay LaboratoryShenzhen518132P. R. China
| | - Yongping Xu
- State Key Laboratory of Protein and Plant Gene ResearchBiomedical Pioneering Innovation Center (BIOPIC)Peking UniversityBeijing100871P. R. China
| | - Dongbao Yin
- State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesBeijing National Laboratory for Molecular SciencesNational Biomedical Imaging CenterCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871P. R. China
| | - Xin Zhu
- Center of Single‐Molecule SciencesFrontiers Science Center for New Organic MatterInstitute of Modern OpticsCollege of Electronic Information and Optical EngineeringNankai University38 Tongyan Road, Jinnan DistrictTianjin300350P. R. China
| | - Huanyan Fu
- Center of Single‐Molecule SciencesFrontiers Science Center for New Organic MatterInstitute of Modern OpticsCollege of Electronic Information and Optical EngineeringNankai University38 Tongyan Road, Jinnan DistrictTianjin300350P. R. China
| | - Xiaodong Su
- State Key Laboratory of Protein and Plant Gene ResearchBiomedical Pioneering Innovation Center (BIOPIC)Peking UniversityBeijing100871P. R. China
| | - Xuefeng Guo
- State Key Laboratory for Structural Chemistry of Unstable and Stable SpeciesBeijing National Laboratory for Molecular SciencesNational Biomedical Imaging CenterCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871P. R. China
- Center of Single‐Molecule SciencesFrontiers Science Center for New Organic MatterInstitute of Modern OpticsCollege of Electronic Information and Optical EngineeringNankai University38 Tongyan Road, Jinnan DistrictTianjin300350P. R. China
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13
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Shetty RM, Brady SR, Rothemund PWK, Hariadi RF, Gopinath A. Bench-Top Fabrication of Single-Molecule Nanoarrays by DNA Origami Placement. ACS NANO 2021; 15:11441-11450. [PMID: 34228915 PMCID: PMC9701110 DOI: 10.1021/acsnano.1c01150] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Large-scale nanoarrays of single biomolecules enable high-throughput assays while unmasking the underlying heterogeneity within ensemble populations. Until recently, creating such grids which combine the advantages of microarrays and single-molecule experiments (SMEs) has been particularly challenging due to the mismatch between the size of these molecules and the resolution of top-down fabrication techniques. DNA origami placement (DOP) combines two powerful techniques to address this issue: (i) DNA origami, which provides a ∼100 nm self-assembled template for single-molecule organization with 5 nm resolution and (ii) top-down lithography, which patterns these DNA nanostructures, transforming them into functional nanodevices via large-scale integration with arbitrary substrates. Presently, this technique relies on state-of-the-art infrastructure and highly trained personnel, making it prohibitively expensive for researchers. Here, we introduce a cleanroom-free, $1 benchtop technique to create meso-to-macro-scale DNA origami nanoarrays using self-assembled colloidal nanoparticles, thereby circumventing the need for top-down fabrication. We report a maximum yield of 74%, 2-fold higher than the statistical limit of 37% imposed on non-specific molecular loading alternatives. Furthermore, we provide a proof-of-principle for the ability of this nanoarray platform to transform traditionally low-throughput, stochastic, single-molecule assays into high-throughput, deterministic ones, without compromising data quality. Our approach has the potential to democratize single-molecule nanoarrays and demonstrates their utility as a tool for biophysical assays and diagnostics.
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Affiliation(s)
- Rishabh M. Shetty
- Biodesign Center for Molecular Design and Biomimetics (at the Biodesign Institute) at Arizona State University, Tempe, Arizona 85287, United States; School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287, United States
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Sarah R. Brady
- Biodesign Center for Molecular Design and Biomimetics (at the Biodesign Institute) at Arizona State University, Tempe, Arizona 85287, United States
| | - Paul W. K. Rothemund
- Department of Bioengineering, Computational and Mathematical Sciences, and Computation and Neural Systems, California Institute of Technology, Pasadena, California 91125, United States
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14
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Jarillo J, Ibarra B, Cao-García FJ. DNA replication: In vitro single-molecule manipulation data analysis and models. Comput Struct Biotechnol J 2021; 19:3765-3778. [PMID: 34285777 PMCID: PMC8267548 DOI: 10.1016/j.csbj.2021.06.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 06/18/2021] [Accepted: 06/21/2021] [Indexed: 11/05/2022] Open
Abstract
Data analysis allows to extract information from the noisy single-molecule data. Models provide insight in the underlying biochemical processes. Ligands can activate or inhibit DNA replication and DNA unwinding.
DNA replication is a key biochemical process of the cell cycle. In the last years, analysis of in vitro single-molecule DNA replication events has provided new information that cannot be obtained with ensembles studies. Here, we introduce crucial techniques for the proper analysis and modelling of DNA replication in vitro single-molecule manipulation data. Specifically, we review some of the main methods to analyze and model the real-time kinetics of the two main molecular motors of the replisome: DNA polymerase and DNA helicase. Our goal is to facilitate access to and understanding of these techniques to promotetheir use in the study of DNA replication at the single-molecule level. A proper analysis of single-molecule data is crucial to obtain a detailed picture of, among others, the kinetics rates, equilibrium contants and conformational changes of the system under study. The techniques presented here have been used or can be adapted to study the operation of other proteins involved in nucleic acids metabolism.
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Affiliation(s)
- Javier Jarillo
- University of Namur, Institute of Life-Earth-Environment, Namur Center for Complex Systems, Rue de Bruxelles 61, 5000 Namur, Belgium
| | - Borja Ibarra
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, C/ Faraday 9, 28049 Madrid, Spain
| | - Francisco Javier Cao-García
- Instituto Madrileño de Estudios Avanzados en Nanociencia, IMDEA Nanociencia, C/ Faraday 9, 28049 Madrid, Spain.,Departamento de Estructura de la Materia, Física Térmica y Electrónica, Universidad Complutense de Madrid, Pza. de Ciencias, 1, 28040 Madrid, Spain
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15
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Buglione E, Salerno D, Marrano CA, Cassina V, Vesco G, Nardo L, Dacasto M, Rigo R, Sissi C, Mantegazza F. Nanomechanics of G-quadruplexes within the promoter of the KIT oncogene. Nucleic Acids Res 2021; 49:4564-4573. [PMID: 33849064 PMCID: PMC8096272 DOI: 10.1093/nar/gkab079] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/07/2021] [Accepted: 04/09/2021] [Indexed: 12/31/2022] Open
Abstract
G-quadruplexes (G4s) are tetrahelical DNA structures stabilized by four guanines paired via Hoogsteen hydrogen bonds into quartets. While their presence within eukaryotic DNA is known to play a key role in regulatory processes, their functional mechanisms are still under investigation. In the present work, we analysed the nanomechanical properties of three G4s present within the promoter of the KIT proto-oncogene from a single-molecule point of view through the use of magnetic tweezers (MTs). The study of DNA extension fluctuations under negative supercoiling allowed us to identify a characteristic fingerprint of G4 folding. We further analysed the energetic contribution of G4 to the double-strand denaturation process in the presence of negative supercoiling, and we observed a reduction in the energy required for strands separation.
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Affiliation(s)
- Enrico Buglione
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Domenico Salerno
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Claudia Adriana Marrano
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Valeria Cassina
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Guglielmo Vesco
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Luca Nardo
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
| | - Mauro Dacasto
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020 Legnaro (PD), Italy
| | - Riccardo Rigo
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova (PD), Italy
| | - Claudia Sissi
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova (PD), Italy.,Interdepartmental Research Center for Innovative Biotechnologies (CRIBI), University of Padova, 35121 Padova (PD), Italy
| | - Francesco Mantegazza
- School of Medicine and Surgery, BioNanoMedicine Center NANOMIB, University of Milano-Bicocca, 20854 Vedano al Lambro (MB), Italy
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16
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Bocanegra R, Ismael Plaza GA, Pulido CR, Ibarra B. DNA replication machinery: Insights from in vitro single-molecule approaches. Comput Struct Biotechnol J 2021; 19:2057-2069. [PMID: 33995902 PMCID: PMC8085672 DOI: 10.1016/j.csbj.2021.04.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/03/2021] [Accepted: 04/03/2021] [Indexed: 11/16/2022] Open
Abstract
The replisome is the multiprotein molecular machinery that replicates DNA. The replisome components work in precise coordination to unwind the double helix of the DNA and replicate the two strands simultaneously. The study of DNA replication using in vitro single-molecule approaches provides a novel quantitative understanding of the dynamics and mechanical principles that govern the operation of the replisome and its components. ‘Classical’ ensemble-averaging methods cannot obtain this information. Here we describe the main findings obtained with in vitro single-molecule methods on the performance of individual replisome components and reconstituted prokaryotic and eukaryotic replisomes. The emerging picture from these studies is that of stochastic, versatile and highly dynamic replisome machinery in which transient protein-protein and protein-DNA associations are responsible for robust DNA replication.
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Affiliation(s)
- Rebeca Bocanegra
- IMDEA Nanociencia, Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain
| | - G A Ismael Plaza
- IMDEA Nanociencia, Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain
| | - Carlos R Pulido
- IMDEA Nanociencia, Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain
| | - Borja Ibarra
- IMDEA Nanociencia, Faraday 9, Campus Cantoblanco, 28049 Madrid, Spain
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17
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Chen CS, Shiu RF, Hsieh YY, Xu C, Vazquez CI, Cui Y, Hsu IC, Quigg A, Santschi PH, Chin WC. Stickiness of extracellular polymeric substances on different surfaces via magnetic tweezers. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 757:143766. [PMID: 33243507 DOI: 10.1016/j.scitotenv.2020.143766] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 11/08/2020] [Accepted: 11/08/2020] [Indexed: 06/11/2023]
Abstract
Organic particle dynamics in the surface ocean plays a critical part in the marine carbon cycle. Aggregation of marine organic particles drives their downward transport to support various marine organisms on their transit to the sediments. Extracellular polymeric substances (EPS) from various microbes are a major contributor to the oceanic organic particle pool. The stickiness of EPS is expected to play a determining role in the aggregation process of particles; however, stickiness parameters are usually indirectly estimated through data fitting without direct assessment. Here a magnetic tweezer method was developed to quantitatively assess the stickiness of three model EPS produced by: Amphora sp., (diatom), Emiliania huxleyi (coccolithophore), and Sagittula stellata (bacteria), under different in vitro environmental conditions (salinity or EDTA complexed cations) and surface matrices (EPS-EPS and bare glass). Our results showed the stickiness of three microbial EPS decreasing for S. stellata > E. huxleyi > Amphora sp., in line with their decreasing protein-to-carbohydrate (P/C) ratios (related to their relative hydrophobicity). The data not only emphasize the importance of hydrophobicity on EPS stickiness, but also demonstrates that salinity and the nature of the substrate surface can influence the stickiness. Furthermore, we investigated stickiness between various types of EPS, and the observed selective stickiness of EPS between species may shed light on the interactions among heterogeneous marine microorganisms. Overall, this newly developed system provides a platform to assess the EPS stickiness to advance our understanding of the aggregation and sedimentation process of organic particles that are critical for the fate of organic carbon as well as for biofilm formation and microbial colonization of surfaces in the ocean.
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Affiliation(s)
- Chi-Shuo Chen
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ruei-Feng Shiu
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 20224, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Yu-Ying Hsieh
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Chen Xu
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX 77553, USA
| | - Carlos I Vazquez
- Department of Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA
| | - Yujia Cui
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Ian C Hsu
- Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Antonietta Quigg
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, TX 77553, USA; Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Peter H Santschi
- Department of Marine and Coastal Environmental Science, Texas A&M University at Galveston, Galveston, TX 77553, USA; Department of Oceanography, Texas A&M University, College Station, TX 77843, USA
| | - Wei-Chun Chin
- Department of Bioengineering, School of Engineering, University of California at Merced, Merced, CA 95343, USA.
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18
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Papini FS, Seifert M, Dulin D. High-yield fabrication of DNA and RNA constructs for single molecule force and torque spectroscopy experiments. Nucleic Acids Res 2020; 47:e144. [PMID: 31584079 PMCID: PMC6902051 DOI: 10.1093/nar/gkz851] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/20/2019] [Accepted: 10/02/2019] [Indexed: 12/19/2022] Open
Abstract
Single molecule biophysics experiments have enabled the observation of biomolecules with a great deal of precision in space and time, e.g. nucleic acids mechanical properties and protein–nucleic acids interactions using force and torque spectroscopy techniques. The success of these experiments strongly depends on the capacity of the researcher to design and fabricate complex nucleic acid structures, as the outcome and the yield of the experiment also strongly depend on the high quality and purity of the final construct. Though the molecular biology techniques involved are well known, the fabrication of nucleic acid constructs for single molecule experiments still remains a difficult task. Here, we present new protocols to generate high quality coilable double-stranded DNA and RNA, as well as DNA and RNA hairpins with ∼500–1000 bp long stems. Importantly, we present a new approach based on single-stranded DNA (ssDNA) annealing and we use magnetic tweezers to show that this approach simplifies the fabrication of complex DNA constructs, such as hairpins, and converts more efficiently the input DNA into construct than the standard PCR-digestion-ligation approach. The protocols we describe here enable the design of a large range of nucleic acid construct for single molecule biophysics experiments.
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Affiliation(s)
- Flávia S Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
| | - Mona Seifert
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Cauerstrasse 3, 91058 Erlangen, Germany
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19
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Multi-parameter measurements of conformational dynamics in nucleic acids and nucleoprotein complexes. Methods 2019; 169:69-77. [PMID: 31228549 DOI: 10.1016/j.ymeth.2019.06.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/15/2019] [Accepted: 06/18/2019] [Indexed: 11/20/2022] Open
Abstract
Biological macromolecules undergo dynamic conformational changes. Single-molecule methods can track such structural rearrangements in real time. However, while the structure of large macromolecules may change along many degrees of freedom, single-molecule techniques only monitor a limited number of these axes of motion. Advanced single-molecule methods are being developed to track multiple degrees of freedom in nucleic acids and nucleoprotein complexes at high resolution, to enable better manipulation and control of the system under investigation, and to collect measurements in massively parallel fashion. Combining complementary single-molecule methods within the same assay also provides unique measurement opportunities. Implementations of magnetic and optical tweezers combined with fluorescence and FRET have demonstrated results unattainable by either technique alone. Augmenting other advanced single-molecule methods with fluorescence detection will allow us to better capture the multidimensional dynamics of nucleic acids and nucleoprotein complexes central to biology.
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20
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Li N, Wang J, Ma K, Liang L, Mi L, Huang W, Ma X, Wang Z, Zheng W, Xu L, Chen JH, Yu Z. The dynamics of forming a triplex in an artificial telomere inferred by DNA mechanics. Nucleic Acids Res 2019; 47:e86. [PMID: 31114915 PMCID: PMC6735771 DOI: 10.1093/nar/gkz464] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 05/06/2019] [Accepted: 05/15/2019] [Indexed: 11/21/2022] Open
Abstract
A telomere carrying repetitive sequences ends with a single-stranded overhang. The G-rich overhang could fold back and bind in the major groove of its upstream duplex, forming an antiparallel triplex structure. The telomeric triplex has been proposed to function in protecting chromosome ends. However, we lack strategies to mechanically probe the dynamics of a telomeric triplex. Here, we show that the topological dynamics of a telomeric triplex involves 3' overhang binding at the ds/ssDNA junction inferred by DNA mechanics. Assisted by click chemistry and branched polymerase chain reaction, we developed a rescue-rope-strategy for mechanically manipulating an artificial telomeric DNA with a free end. Using single-molecule magnetic tweezers, we identified a rarely forming (5%) telomeric triplex which pauses at an intermediate state upon unzipping the Watson-Crick paired duplex. Our findings revealed that a mechanically stable triplex formed in a telomeric DNA can resist a force of 20 pN for a few seconds in a physiological buffer. We also demonstrated that the rescue-rope-strategy assisted mechanical manipulation can directly rupture the interactions between the third strand and its targeting duplex in a DNA triplex. Our single-molecule rescue-rope-strategy will serve as a general tool to investigate telomere dynamics and further develop triplex-based biotechnologies.
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Affiliation(s)
- Ning Li
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Junli Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Kangkang Ma
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Lin Liang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Lipei Mi
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China
| | - Wei Huang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Xiaofeng Ma
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Zeyu Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Wei Zheng
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
| | - Linyan Xu
- State Key Laboratory of Precision Measuring Technology and Instruments, Tianjin University, Tianjin 300072, China
| | - Jun-Hu Chen
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai 200025, China
| | - Zhongbo Yu
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Haihe Education Park, 38 Tongyan Road, Tianjin 300353, China
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21
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Cui TJ, Joo C. Facilitated diffusion of Argonaute-mediated target search. RNA Biol 2019; 16:1093-1107. [PMID: 31068066 PMCID: PMC6693542 DOI: 10.1080/15476286.2019.1616353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 04/29/2019] [Accepted: 05/01/2019] [Indexed: 10/26/2022] Open
Abstract
Argonaute (Ago) proteins are of key importance in many cellular processes. In eukaryotes, Ago can induce translational repression followed by deadenylation and degradation of mRNA molecules through base pairing of microRNAs (miRNAs) with a complementary target on a mRNA sequence. In bacteria, Ago eliminates foreign DNA through base pairing of siDNA (small interfering DNA) with a target on a DNA sequence. Effective targeting activities of Ago require fast recognition of the cognate target sequence among numerous off-target sites. Other target search proteins such as transcription factors (TFs) are known to rely on facilitated diffusion for this goal, but it is undetermined to what extent these small nucleic acid-guided proteins utilize this mechanism. Here, we review recent single-molecule studies on Ago target search. We discuss the consequences of the recent findings on the search mechanism. Furthermore, we discuss the open standing research questions that need to be addressed for a complete picture of facilitated target search by small nucleic acids.
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Affiliation(s)
- Tao Ju Cui
- Kavli Institute of Nanoscience and Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
| | - Chirlmin Joo
- Kavli Institute of Nanoscience and Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
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22
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Tauran Y, Kumemura M, Tarhan MC, Perret G, Perret F, Jalabert L, Collard D, Fujita H, Coleman AW. Direct measurement of the mechanical properties of a chromatin analog and the epigenetic effects of para-sulphonato-calix[4]arene. Sci Rep 2019; 9:5816. [PMID: 30967623 PMCID: PMC6456576 DOI: 10.1038/s41598-019-42267-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 03/25/2019] [Indexed: 02/06/2023] Open
Abstract
By means of Silicon Nano Tweezers (SNTs) the effects on the mechanical properties of λ-phage DNA during interaction with calf thymus nucleosome to form an artificial chromatin analog were measured. At a concentration of 100 nM, a nucleosome solution induced a strong stiffening effect on DNA (1.1 N m-1). This can be compared to the effects of the histone proteins, H1, H2A, H3 where no changes in the mechanical properties of DNA were observed and the complex of the H3/H4 proteins where a smaller increase in the stiffness is observed (0.2 N m-1). Para-sulphonato-calix[4]arene, SC4, known for epigenetic activity by interacting specifically with the lysine groups of histone proteins, was studied for its effect on an artificial chromatin. Using a microfluidic SNT device, SC4 was titrated against the artificial chromatin, at a concentration of 1 mM in SC4 a considerable increase in stiffness, 15 N m-1, was observed. Simultaneously optical microscopy showed a physical change in the DNA structure between the tips of the SNT device. Electronic and Atomic Force microscopy confirmed this structural re-arrangement. Negative control experiments confirmed that these mechanical and physical effects were induced neither by the acidity of SC4 nor through nonspecific interactions of SC4 on DNA.
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Affiliation(s)
- Yannick Tauran
- LMI CNRS UMR 5615, Université Lyon 1, Villeurbanne, 69622, France.
- LIMMS/CNRS-IIS UMI 2820, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan.
| | - Momoko Kumemura
- LIMMS/CNRS-IIS UMI 2820, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
- CIRMM, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
- Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, Fukuoka, 808-0196, Japan
| | - Mehmet C Tarhan
- Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520-IEMN, Lille, F59000, France
- CNRS/IIS/COL/Lille 1 SMMiL-E project, 59046, Lille Cedex, France
| | - Grégoire Perret
- LIMMS/CNRS-IIS UMI 2820, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
- CNRS/IIS/COL/Lille 1 SMMiL-E project, 59046, Lille Cedex, France
| | - Florent Perret
- ICBMS, CNRS UMR 5246, Université Lyon 1, Villeurbanne, 69622, France
| | - Laurent Jalabert
- LIMMS/CNRS-IIS UMI 2820, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
- CIRMM, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
| | - Dominique Collard
- LIMMS/CNRS-IIS UMI 2820, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
- CNRS/IIS/COL/Lille 1 SMMiL-E project, 59046, Lille Cedex, France
| | - Hiroyuki Fujita
- LIMMS/CNRS-IIS UMI 2820, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
- CIRMM, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
| | - Anthony W Coleman
- CIRMM, Institute of Industrial Science, The University of Tokyo, Tokyo, 153-8505, Japan
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23
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Hill FR, van Oijen AM, Duderstadt KE. Detection of kinetic change points in piece-wise linear single molecule motion. J Chem Phys 2018; 148:123317. [PMID: 29604840 DOI: 10.1063/1.5009387] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Single-molecule approaches present a powerful way to obtain detailed kinetic information at the molecular level. However, the identification of small rate changes is often hindered by the considerable noise present in such single-molecule kinetic data. We present a general method to detect such kinetic change points in trajectories of motion of processive single molecules having Gaussian noise, with a minimum number of parameters and without the need of an assumed kinetic model beyond piece-wise linearity of motion. Kinetic change points are detected using a likelihood ratio test in which the probability of no change is compared to the probability of a change occurring, given the experimental noise. A predetermined confidence interval minimizes the occurrence of false detections. Applying the method recursively to all sub-regions of a single molecule trajectory ensures that all kinetic change points are located. The algorithm presented allows rigorous and quantitative determination of kinetic change points in noisy single molecule observations without the need for filtering or binning, which reduce temporal resolution and obscure dynamics. The statistical framework for the approach and implementation details are discussed. The detection power of the algorithm is assessed using simulations with both single kinetic changes and multiple kinetic changes that typically arise in observations of single-molecule DNA-replication reactions. Implementations of the algorithm are provided in ImageJ plugin format written in Java and in the Julia language for numeric computing, with accompanying Jupyter Notebooks to allow reproduction of the analysis presented here.
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Affiliation(s)
- Flynn R Hill
- Centre for Medical and Molecular Bioscience, Illawarra Health and Medical Research Institute and University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Antoine M van Oijen
- Centre for Medical and Molecular Bioscience, Illawarra Health and Medical Research Institute and University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Karl E Duderstadt
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
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24
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Ostrofet E, Papini FS, Dulin D. Correction-free force calibration for magnetic tweezers experiments. Sci Rep 2018; 8:15920. [PMID: 30374099 PMCID: PMC6206022 DOI: 10.1038/s41598-018-34360-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 10/12/2018] [Indexed: 11/09/2022] Open
Abstract
Magnetic tweezers are a powerful technique to perform high-throughput and high-resolution force spectroscopy experiments at the single-molecule level. The camera-based detection of magnetic tweezers enables the observation of hundreds of magnetic beads in parallel, and therefore the characterization of the mechanochemical behavior of hundreds of nucleic acids and enzymes. However, magnetic tweezers experiments require an accurate force calibration to extract quantitative data, which is limited to low forces if the deleterious effect of the finite camera open shutter time (τsh) is not corrected. Here, we provide a simple method to perform correction-free force calibration for high-throughput magnetic tweezers at low image acquisition frequency (fac). By significantly reducing τsh to at least 4-fold the characteristic times of the tethered magnetic bead, we accurately evaluated the variance of the magnetic bead position along the axis parallel to the magnetic field, estimating the force with a relative error of ~10% (standard deviation), being only limited by the bead-to-bead difference. We calibrated several magnets - magnetic beads configurations, covering a force range from ~50 fN to ~60 pN. In addition, for the presented configurations, we provide a table with the mathematical expressions that describe the force as a function of the magnets position.
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Affiliation(s)
- Eugen Ostrofet
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany
| | - Flávia Stal Papini
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany
| | - David Dulin
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich Alexander University Erlangen-Nürnberg (FAU), Hartmannstr. 14, 91052, Erlangen, Germany.
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25
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van Oene MM, Ha S, Jager T, Lee M, Pedaci F, Lipfert J, Dekker NH. Quantifying the Precision of Single-Molecule Torque and Twist Measurements Using Allan Variance. Biophys J 2018; 114:1970-1979. [PMID: 29694873 DOI: 10.1016/j.bpj.2018.02.039] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 02/12/2018] [Accepted: 02/27/2018] [Indexed: 01/06/2023] Open
Abstract
Single-molecule manipulation techniques have provided unprecedented insights into the structure, function, interactions, and mechanical properties of biological macromolecules. Recently, the single-molecule toolbox has been expanded by techniques that enable measurements of rotation and torque, such as the optical torque wrench (OTW) and several different implementations of magnetic (torque) tweezers. Although systematic analyses of the position and force precision of single-molecule techniques have attracted considerable attention, their angle and torque precision have been treated in much less detail. Here, we propose Allan deviation as a tool to systematically quantitate angle and torque precision in single-molecule measurements. We apply the Allan variance method to experimental data from our implementations of (electro)magnetic torque tweezers and an OTW and find that both approaches can achieve a torque precision better than 1 pN · nm. The OTW, capable of measuring torque on (sub)millisecond timescales, provides the best torque precision for measurement times ≲10 s, after which drift becomes a limiting factor. For longer measurement times, magnetic torque tweezers with their superior stability provide the best torque precision. Use of the Allan deviation enables critical assessments of the torque precision as a function of measurement time across different measurement modalities and provides a tool to optimize measurement protocols for a given instrument and application.
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Affiliation(s)
- Maarten M van Oene
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Seungkyu Ha
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Tessa Jager
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Mina Lee
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Francesco Pedaci
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands
| | - Jan Lipfert
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands; Department of Physics, Nanosystems Initiative Munich, and Center for Nanoscience, LMU Munich, Munich, Germany.
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, the Netherlands.
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26
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Dulin D, Bauer DLV, Malinen AM, Bakermans JJW, Kaller M, Morichaud Z, Petushkov I, Depken M, Brodolin K, Kulbachinskiy A, Kapanidis AN. Pausing controls branching between productive and non-productive pathways during initial transcription in bacteria. Nat Commun 2018; 9:1478. [PMID: 29662062 PMCID: PMC5902446 DOI: 10.1038/s41467-018-03902-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 03/20/2018] [Indexed: 01/25/2023] Open
Abstract
Transcription in bacteria is controlled by multiple molecular mechanisms that precisely regulate gene expression. It has been recently shown that initial RNA synthesis by the bacterial RNA polymerase (RNAP) is interrupted by pauses; however, the pausing determinants and the relationship of pausing with productive and abortive RNA synthesis remain poorly understood. Using single-molecule FRET and biochemical analysis, here we show that the pause encountered by RNAP after the synthesis of a 6-nt RNA (ITC6) renders the promoter escape strongly dependent on the NTP concentration. Mechanistically, the paused ITC6 acts as a checkpoint that directs RNAP to one of three competing pathways: productive transcription, abortive RNA release, or a new unscrunching/scrunching pathway. The cyclic unscrunching/scrunching of the promoter generates a long-lived, RNA-bound paused state; the abortive RNA release and DNA unscrunching are thus not as tightly linked as previously thought. Finally, our new model couples the pausing with the abortive and productive outcomes of initial transcription.
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Affiliation(s)
- David Dulin
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK.
- Junior Research Group 2, Interdisciplinary Center for Clinical Research, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Hartmannstrasse 14, 91052, Erlangen, Germany.
| | - David L V Bauer
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Anssi M Malinen
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
- Department of Biochemistry, University of Turku, 20014, Turku, Finland
| | - Jacob J W Bakermans
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Martin Kaller
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK
| | - Zakia Morichaud
- Institut de Recherche en Infectiologie de Montpellier (IRIM) UMR9004 CNRS-Université de Montpellier, 1919 Route de Mende, 34293, Montpellier, France
| | - Ivan Petushkov
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ, Delft, The Netherlands
| | - Konstantin Brodolin
- Institut de Recherche en Infectiologie de Montpellier (IRIM) UMR9004 CNRS-Université de Montpellier, 1919 Route de Mende, 34293, Montpellier, France
| | - Andrey Kulbachinskiy
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, 123182, Russia
| | - Achillefs N Kapanidis
- Biological Physics Research Group, Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU, UK.
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27
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Ivanov IE, Lebel P, Oberstrass FC, Starr CH, Parente AC, Ierokomos A, Bryant Z. Multimodal Measurements of Single-Molecule Dynamics Using FluoRBT. Biophys J 2018; 114:278-282. [PMID: 29248150 PMCID: PMC5984952 DOI: 10.1016/j.bpj.2017.11.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/15/2017] [Accepted: 11/08/2017] [Indexed: 11/21/2022] Open
Abstract
Single-molecule methods provide direct measurements of macromolecular dynamics, but are limited by the number of degrees of freedom that can be followed at one time. High-resolution rotor bead tracking (RBT) measures DNA torque, twist, and extension, and can be used to characterize the structural dynamics of DNA and diverse nucleoprotein complexes. Here, we extend RBT to enable simultaneous monitoring of additional degrees of freedom. Fluorescence-RBT (FluoRBT) combines magnetic tweezers, infrared evanescent scattering, and single-molecule FRET imaging, providing real-time multiparameter measurements of complex molecular processes. We demonstrate the capabilities of FluoRBT by conducting simultaneous measurements of extension and FRET during opening and closing of a DNA hairpin under tension, and by observing simultaneous changes in FRET and torque during a transition between right-handed B-form and left-handed Z-form DNA under controlled supercoiling. We discover unanticipated continuous changes in FRET with applied torque, and also show how FluoRBT can facilitate high-resolution FRET measurements of molecular states, by using a mechanical signal as an independent temporal reference for aligning and averaging noisy fluorescence data. By combining mechanical measurements of global DNA deformations with FRET measurements of local conformational changes, FluoRBT will enable multidimensional investigations of systems ranging from DNA structures to large macromolecular machines.
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Affiliation(s)
- Ivan E Ivanov
- Department of Chemical Engineering, Stanford University, Stanford, California; Department of Bioengineering, Stanford University, Stanford, California
| | - Paul Lebel
- Department of Bioengineering, Stanford University, Stanford, California; Department of Applied Physics, Stanford University, Stanford, California
| | | | - Charles H Starr
- Department of Bioengineering, Stanford University, Stanford, California; Program in Biophysics, Stanford University, Stanford, California
| | - Angelica C Parente
- Department of Bioengineering, Stanford University, Stanford, California; Program in Biophysics, Stanford University, Stanford, California
| | - Athena Ierokomos
- Department of Bioengineering, Stanford University, Stanford, California; Program in Biophysics, Stanford University, Stanford, California
| | - Zev Bryant
- Department of Bioengineering, Stanford University, Stanford, California; Department of Structural Biology, Stanford University, Stanford, California.
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28
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Scherr MJ, Safaric B, Duderstadt KE. Noise in the Machine: Alternative Pathway Sampling is the Rule During DNA Replication. Bioessays 2017; 40. [PMID: 29282758 DOI: 10.1002/bies.201700159] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/01/2017] [Indexed: 11/07/2022]
Abstract
The astonishing efficiency and accuracy of DNA replication has long suggested that refined rules enforce a single highly reproducible sequence of molecular events during the process. This view was solidified by early demonstrations that DNA unwinding and synthesis are coupled within a stable molecular factory, known as the replisome, which consists of conserved components that each play unique and complementary roles. However, recent single-molecule observations of replisome dynamics have begun to challenge this view, revealing that replication may not be defined by a uniform sequence of events. Instead, multiple exchange pathways, pauses, and DNA loop types appear to dominate replisome function. These observations suggest we must rethink our fundamental assumptions and acknowledge that each replication cycle may involve sampling of alternative, sometimes parallel, pathways. Here, we review our current mechanistic understanding of DNA replication while highlighting findings that exemplify multi-pathway aspects of replisome function and considering the broader implications.
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Affiliation(s)
- Matthias J Scherr
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Barbara Safaric
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Karl E Duderstadt
- Structure and Dynamics of Molecular Machines, Max Planck Institute of Biochemistry, Martinsried, Germany.,Physik Department, Technische Universität München, Garching, Germany
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29
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Chen Y, Ju L, Rushdi M, Ge C, Zhu C. Receptor-mediated cell mechanosensing. Mol Biol Cell 2017; 28:3134-3155. [PMID: 28954860 PMCID: PMC5687017 DOI: 10.1091/mbc.e17-04-0228] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 09/06/2017] [Accepted: 09/19/2017] [Indexed: 12/22/2022] Open
Abstract
Mechanosensing depicts the ability of a cell to sense mechanical cues, which under some circumstances is mediated by the surface receptors. In this review, a four-step model is described for receptor-mediated mechanosensing. Platelet GPIb, T-cell receptor, and integrins are used as examples to illustrate the key concepts and players in this process. Mechanosensing describes the ability of a cell to sense mechanical cues of its microenvironment, including not only all components of force, stress, and strain but also substrate rigidity, topology, and adhesiveness. This ability is crucial for the cell to respond to the surrounding mechanical cues and adapt to the changing environment. Examples of responses and adaptation include (de)activation, proliferation/apoptosis, and (de)differentiation. Receptor-mediated cell mechanosensing is a multistep process that is initiated by binding of cell surface receptors to their ligands on the extracellular matrix or the surface of adjacent cells. Mechanical cues are presented by the ligand and received by the receptor at the binding interface; but their transmission over space and time and their conversion into biochemical signals may involve other domains and additional molecules. In this review, a four-step model is described for the receptor-mediated cell mechanosensing process. Platelet glycoprotein Ib, T-cell receptor, and integrins are used as examples to illustrate the key concepts and players in this process.
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Affiliation(s)
- Yunfeng Chen
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332.,Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332
| | - Lining Ju
- Charles Perkins Centre and Heart Research Institute, University of Sydney, Camperdown, NSW 2006, Australia
| | - Muaz Rushdi
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Chenghao Ge
- Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
| | - Cheng Zhu
- Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332 .,Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332
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30
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Alphonse S, Ghose R. Cystoviral RNA-directed RNA polymerases: Regulation of RNA synthesis on multiple time and length scales. Virus Res 2017; 234:135-152. [PMID: 28104452 PMCID: PMC5476504 DOI: 10.1016/j.virusres.2017.01.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Revised: 01/04/2017] [Accepted: 01/09/2017] [Indexed: 12/18/2022]
Abstract
Role of the RNA polymerase in the cystoviral life-cycle. Spatio-temporal regulation of RNA synthesis in cystoviruses. Emerging role of conformational dynamics in polymerase function.
P2, an RNA-directed RNA polymerase (RdRP), is encoded on the largest of the three segments of the double-stranded RNA genome of cystoviruses. P2 performs the dual tasks of replication and transcription de novo on single-stranded RNA templates, and plays a critical role in the viral life-cycle. Work over the last few decades has yielded a wealth of biochemical and structural information on the functional regulation of P2, on its role in the spatiotemporal regulation of RNA synthesis and its variability across the Cystoviridae family. These range from atomic resolution snapshots of P2 trapped in functionally significant states, in complex with catalytic/structural metal ions, polynucleotide templates and substrate nucleoside triphosphates, to P2 in the context of viral capsids providing structural insight into the assembly of supramolecular complexes and regulatory interactions therein. They include in vitro biochemical studies using P2 purified to homogeneity and in vivo studies utilizing infectious core particles. Recent advances in experimental techniques have also allowed access to the temporal dimension and enabled the characterization of dynamics of P2 on the sub-nanosecond to millisecond timescale through measurements of nuclear spin relaxation in solution and single molecule studies of transcription from seconds to minutes. Below we summarize the most significant results that provide critical insight into the role of P2 in regulating RNA synthesis in cystoviruses.
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Affiliation(s)
- Sébastien Alphonse
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, United States.
| | - Ranajeet Ghose
- Department of Chemistry and Biochemistry, The City College of New York, New York, NY 10031, United States; Graduate Programs in Biochemistry, The Graduate Center of CUNY, New York, NY 10016, United States; Graduate Programs in Chemistry, The Graduate Center of CUNY, New York, NY 10016, United States; Graduate Programs in Physics, The Graduate Center of CUNY, New York, NY 10016, United States.
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31
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Frykholm K, Nyberg LK, Westerlund F. Exploring DNA–protein interactions on the single DNA molecule level using nanofluidic tools. Integr Biol (Camb) 2017; 9:650-661. [DOI: 10.1039/c7ib00085e] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This review highlights the use of nanofluidic channels for studying DNA–protein interactions on the single DNA molecule level.
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Affiliation(s)
- Karolin Frykholm
- Department of Biology and Biological Engineering
- Chalmers University of Technology
- Gothenburg
- Sweden
| | - Lena K. Nyberg
- Department of Biology and Biological Engineering
- Chalmers University of Technology
- Gothenburg
- Sweden
| | - Fredrik Westerlund
- Department of Biology and Biological Engineering
- Chalmers University of Technology
- Gothenburg
- Sweden
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32
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Monachino E, Spenkelink LM, van Oijen AM. Watching cellular machinery in action, one molecule at a time. J Cell Biol 2016; 216:41-51. [PMID: 27979907 PMCID: PMC5223611 DOI: 10.1083/jcb.201610025] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2016] [Revised: 11/24/2016] [Accepted: 11/29/2016] [Indexed: 12/03/2022] Open
Abstract
Monachino et al. review recent developments in single-molecule biophysical approaches and the cell biological advances they allow. Single-molecule manipulation and imaging techniques have become important elements of the biologist’s toolkit to gain mechanistic insights into cellular processes. By removing ensemble averaging, single-molecule methods provide unique access to the dynamic behavior of biomolecules. Recently, the use of these approaches has expanded to the study of complex multiprotein systems and has enabled detailed characterization of the behavior of individual molecules inside living cells. In this review, we provide an overview of the various force- and fluorescence-based single-molecule methods with applications both in vitro and in vivo, highlighting these advances by describing their applications in studies on cytoskeletal motors and DNA replication. We also discuss how single-molecule approaches have increased our understanding of the dynamic behavior of complex multiprotein systems. These methods have shown that the behavior of multicomponent protein complexes is highly stochastic and less linear and deterministic than previously thought. Further development of single-molecule tools will help to elucidate the molecular dynamics of these complex systems both inside the cell and in solutions with purified components.
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Affiliation(s)
- Enrico Monachino
- Centre for Medical and Molecular Bioscience, Illawarra Health and Medical Research Institute and University of Wollongong, New South Wales 2522, Australia.,Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, Netherlands
| | - Lisanne M Spenkelink
- Centre for Medical and Molecular Bioscience, Illawarra Health and Medical Research Institute and University of Wollongong, New South Wales 2522, Australia.,Zernike Institute for Advanced Materials, University of Groningen, Groningen 9747 AG, Netherlands
| | - Antoine M van Oijen
- Centre for Medical and Molecular Bioscience, Illawarra Health and Medical Research Institute and University of Wollongong, New South Wales 2522, Australia
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33
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Badawi A. The Potential of Omics Technologies in Lyme Disease Biomarker Discovery and Early Detection. Infect Dis Ther 2016; 6:85-102. [PMID: 27900646 PMCID: PMC5336413 DOI: 10.1007/s40121-016-0138-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Indexed: 12/31/2022] Open
Abstract
Lyme borreliosis (LB) is the most prevalent arthropod-borne infectious disease in North America and many countries of the temperate Northern Hemisphere. It is associated with local and systemic manifestations and has persistent post-treatment health complications in some individuals. Innate and acquired immunity-related inflammation is likely to play a critical role in both host defense against Borrelia burgdorferi and disease severity. Large-scale analytical approaches to quantify gene expression (transcriptomics), proteins (proteomics) and metabolites (metabolomics) in LB have recently emerged with a potential to advance the development of disease biomarkers in early, disseminated and posttreatment disease stages. These technologies may permit defining the disease stage and facilitate its early detection to improve diagnosis. They will also likely allow elucidating the underlying molecular pathways to aid in identifying molecular targets for therapy. This article reviews the findings within the field of omics relevant to LB and its prospective utility in developing an array of biomarkers that can be employed in LB diagnosis and detection particularly at the early disease stages.
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Affiliation(s)
- Alaa Badawi
- Public Health Risk Sciences Division, Public Health Agency of Canada, 180 Queen Street West, Toronto, ON, Canada. .,Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, FitzGerald Building, 150 College Street, Toronto, ON, Canada.
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34
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Ordu O, Lusser A, Dekker NH. Recent insights from in vitro single-molecule studies into nucleosome structure and dynamics. Biophys Rev 2016; 8:33-49. [PMID: 28058066 PMCID: PMC5167136 DOI: 10.1007/s12551-016-0212-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 06/17/2016] [Indexed: 01/04/2023] Open
Abstract
Eukaryotic DNA is tightly packed into a hierarchically ordered structure called chromatin in order to fit into the micron-scaled nucleus. The basic unit of chromatin is the nucleosome, which consists of a short piece of DNA wrapped around a core of eight histone proteins. In addition to their role in packaging DNA, nucleosomes impact the regulation of essential nuclear processes such as replication, transcription, and repair by controlling the accessibility of DNA. Thus, knowledge of this fundamental DNA-protein complex is crucial for understanding the mechanisms of gene control. While structural and biochemical studies over the past few decades have provided key insights into both the molecular composition and functional aspects of nucleosomes, these approaches necessarily average over large populations and times. In contrast, single-molecule methods are capable of revealing features of subpopulations and dynamic changes in the structure or function of biomolecules, rendering them a powerful complementary tool for probing mechanistic aspects of DNA-protein interactions. In this review, we highlight how these single-molecule approaches have recently yielded new insights into nucleosomal and subnucleosomal structures and dynamics.
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Affiliation(s)
- Orkide Ordu
- Bionanoscience Department, Kavli Institute of Nanoscience,, Delft University of Technology, Van der Maasweg 9,, 2629 HZ Delft, The Netherlands
| | - Alexandra Lusser
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria
| | - Nynke H. Dekker
- Bionanoscience Department, Kavli Institute of Nanoscience,, Delft University of Technology, Van der Maasweg 9,, 2629 HZ Delft, The Netherlands
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35
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Dulin D, Cui TJ, Cnossen J, Docter MW, Lipfert J, Dekker NH. High Spatiotemporal-Resolution Magnetic Tweezers: Calibration and Applications for DNA Dynamics. Biophys J 2016; 109:2113-25. [PMID: 26588570 DOI: 10.1016/j.bpj.2015.10.018] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 10/05/2015] [Accepted: 10/13/2015] [Indexed: 11/16/2022] Open
Abstract
The observation of biological processes at the molecular scale in real time requires high spatial and temporal resolution. Magnetic tweezers are straightforward to implement, free of radiation or photodamage, and provide ample multiplexing capability, but their spatiotemporal resolution has lagged behind that of other single-molecule manipulation techniques, notably optical tweezers and AFM. Here, we present, to our knowledge, a new high-resolution magnetic tweezers apparatus. We systematically characterize the achievable spatiotemporal resolution for both incoherent and coherent light sources, different types and sizes of beads, and different types and lengths of tethered molecules. Using a bright coherent laser source for illumination and tracking at 6 kHz, we resolve 3 Å steps with a 1 s period for surface-melted beads and 5 Å steps with a 0.5 s period for double-stranded-dsDNA-tethered beads, in good agreement with a model of stochastic bead motion in the magnetic tweezers. We demonstrate how this instrument can be used to monitor the opening and closing of a DNA hairpin on millisecond timescales in real time, together with attendant changes in the hairpin dynamics upon the addition of deoxythymidine triphosphate. Our approach opens up the possibility of observing biological events at submillisecond timescales with subnanometer resolution using camera-based detection.
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Affiliation(s)
- David Dulin
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
| | - Tao Ju Cui
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Jelmer Cnossen
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Margreet W Docter
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Jan Lipfert
- Department of Physics, Nanosystems Initiative Munich and Center for Nanoscience, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
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36
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Berghuis BA, Köber M, van Laar T, Dekker NH. High-throughput, high-force probing of DNA-protein interactions with magnetic tweezers. Methods 2016; 105:90-8. [DOI: 10.1016/j.ymeth.2016.03.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 03/23/2016] [Accepted: 03/29/2016] [Indexed: 12/19/2022] Open
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37
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Probing the mechanical properties, conformational changes, and interactions of nucleic acids with magnetic tweezers. J Struct Biol 2016; 197:26-36. [PMID: 27368129 DOI: 10.1016/j.jsb.2016.06.022] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/06/2016] [Accepted: 06/28/2016] [Indexed: 11/21/2022]
Abstract
Nucleic acids are central to the storage and transmission of genetic information. Mechanical properties, along with their sequence, both enable and fundamentally constrain the biological functions of DNA and RNA. For small deformations from the equilibrium conformations, nucleic acids are well described by an isotropic elastic rod model. However, external forces and torsional strains can induce conformational changes, giving rise to a complex force-torque phase diagram. This review focuses on magnetic tweezers as a powerful tool to precisely determine both the elastic parameters and conformational transitions of nucleic acids under external forces and torques at the single-molecule level. We review several variations of magnetic tweezers, in particular conventional magnetic tweezers, freely orbiting magnetic tweezers and magnetic torque tweezers, and discuss their characteristic capabilities. We then describe the elastic rod model for DNA and RNA and discuss conformational changes induced by mechanical stress. The focus lies on the responses to torque and twist, which are crucial in the mechanics and interactions of nucleic acids and can directly be measured using magnetic tweezers. We conclude by highlighting several recent studies of nucleic acid-protein and nucleic acid-small-molecule interactions as further applications of magnetic tweezers and give an outlook of some exciting developments to come.
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Long X, Parks JW, Stone MD. Integrated magnetic tweezers and single-molecule FRET for investigating the mechanical properties of nucleic acid. Methods 2016; 105:16-25. [PMID: 27320203 DOI: 10.1016/j.ymeth.2016.06.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2016] [Revised: 06/09/2016] [Accepted: 06/13/2016] [Indexed: 02/02/2023] Open
Abstract
Many enzymes promote structural changes in their nucleic acid substrates via application of piconewton forces over nanometer length scales. Magnetic tweezers (MT) is a single molecule force spectroscopy method widely used for studying the energetics of such mechanical processes. MT permits stable application of a wide range of forces and torques over long time scales with nanometer spatial resolution. However, in any force spectroscopy experiment, the ability to monitor structural changes in nucleic acids with nanometer sensitivity requires the system of interest to be held under high degrees of tension to improve signal to noise. This limitation prohibits measurement of structural changes within nucleic acids under physiologically relevant conditions of low stretching forces. To overcome this challenge, researchers have integrated a spatially sensitive fluorescence spectroscopy method, single molecule-FRET, with MT to allow simultaneous observation and manipulation of nanoscale structural transitions over a wide range of forces. Here, we describe a method for using this hybrid instrument to analyze the mechanical properties of nucleic acids. We expect that this method for analysis of nucleic acid structure will be easily adapted for experiments aiming to interrogate the mechanical responses of other biological macromolecules.
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Affiliation(s)
- Xi Long
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Joseph W Parks
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA, USA
| | - Michael D Stone
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA, USA; Center for Molecular Biology of RNA, University of California Santa Cruz, Santa Cruz, CA, USA.
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Kalkman GA, Zhang Y, Monachino E, Mathwig K, Kamminga ME, Pourhossein P, Oomen PE, Stratmann SA, Zhao Z, van Oijen AM, Verpoorte E, Chiechi RC. Bisecting Microfluidic Channels with Metallic Nanowires Fabricated by Nanoskiving. ACS NANO 2016; 10:2852-2859. [PMID: 26836373 DOI: 10.1021/acsnano.5b07996] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
This paper describes the fabrication of millimeter-long gold nanowires that bisect the center of microfluidic channels. We fabricated the nanowires by nanoskiving and then suspended them over a trench in a glass structure. The channel was sealed by bonding it to a complementary poly(dimethylsiloxane) structure. The resulting structures place the nanowires in the region of highest flow, as opposed to the walls, where it approaches zero, and expose their entire surface area to fluid. We demonstrate active functionality, by constructing a hot-wire anemometer to measure flow through determining the change in resistance of the nanowire as a function of heat dissipation at low voltage (<5 V). Further, passive functionality is demonstrated by visualizing individual, fluorescently labeled DNA molecules attached to the wires. We measure rates of flow and show that, compared to surface-bound DNA strands, elongation saturates at lower rates of flow and background fluorescence from nonspecific binding is reduced.
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Affiliation(s)
- Gerard A Kalkman
- Groningen Research Institute of Pharmancy , Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Yanxi Zhang
- Zernike Institute for Advanced Materials , Nijenborgh 4, 9747 AG Groningen, The Netherlands
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Enrico Monachino
- Zernike Institute for Advanced Materials , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Klaus Mathwig
- Groningen Research Institute of Pharmancy , Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Machteld E Kamminga
- Zernike Institute for Advanced Materials , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Parisa Pourhossein
- Zernike Institute for Advanced Materials , Nijenborgh 4, 9747 AG Groningen, The Netherlands
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Pieter E Oomen
- Groningen Research Institute of Pharmancy , Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Sarah A Stratmann
- Zernike Institute for Advanced Materials , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Zhiyuan Zhao
- Zernike Institute for Advanced Materials , Nijenborgh 4, 9747 AG Groningen, The Netherlands
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Antoine M van Oijen
- Zernike Institute for Advanced Materials , Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Elisabeth Verpoorte
- Groningen Research Institute of Pharmancy , Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
| | - Ryan C Chiechi
- Zernike Institute for Advanced Materials , Nijenborgh 4, 9747 AG Groningen, The Netherlands
- Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands
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40
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Dulin D, Vilfan ID, Berghuis BA, Poranen MM, Depken M, Dekker NH. Backtracking behavior in viral RNA-dependent RNA polymerase provides the basis for a second initiation site. Nucleic Acids Res 2015; 43:10421-9. [PMID: 26496948 PMCID: PMC4666362 DOI: 10.1093/nar/gkv1098] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/11/2015] [Indexed: 12/02/2022] Open
Abstract
Transcription in RNA viruses is highly dynamic, with a variety of pauses interrupting nucleotide addition by RNA-dependent RNA polymerase (RdRp). For example, rare but lengthy pauses (>20 s) have been linked to backtracking for viral single-subunit RdRps. However, while such backtracking has been well characterized for multi-subunit RNA polymerases (RNAPs) from bacteria and yeast, little is known about the details of viral RdRp backtracking and its biological roles. Using high-throughput magnetic tweezers, we quantify the backtracking by RdRp from the double-stranded (ds) RNA bacteriophage Φ6, a model system for RdRps. We characterize the probability of entering long backtracks as a function of force and propose a model in which the bias toward backtracking is determined by the base paring at the dsRNA fork. We further discover that extensive backtracking provides access to a new 3′-end that allows for the de novo initiation of a second RdRp. This previously unidentified behavior provides a new mechanism for rapid RNA synthesis using coupled RdRps and hints at a possible regulatory pathway for gene expression during viral RNA transcription.
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Affiliation(s)
- David Dulin
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Igor D Vilfan
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Bojk A Berghuis
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Minna M Poranen
- Department of Biosciences, University of Helsinki, Viikki Biocenter 1, P.O. Box 56 (Viikinkaari 9), 00014 Helsinki, Finland
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
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41
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Untangling reaction pathways through modern approaches to high-throughput single-molecule force-spectroscopy experiments. Curr Opin Struct Biol 2015; 34:116-22. [PMID: 26434413 DOI: 10.1016/j.sbi.2015.08.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 08/06/2015] [Accepted: 08/10/2015] [Indexed: 11/22/2022]
Abstract
Single-molecule experiments provide a unique means for real-time observation of the activity of individual biomolecular machines. Through such techniques, insights into the mechanics of for example, polymerases, helicases, and packaging motors have been gleaned. Here we describe the recent advances in single-molecule force spectroscopy instrumentation that have facilitated high-throughput acquisition at high spatiotemporal resolution. The large datasets attained by such methods can capture rare but important events, and contain information regarding stochastic behaviors covering many orders of magnitude in time. We further discuss analysis of such data sets, and with a special focus on the pause states described in the general literature on RNA polymerase pausing we compare and contrast the signatures of different reaction pathways.
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van Oene MM, Dickinson LE, Pedaci F, Köber M, Dulin D, Lipfert J, Dekker NH. Biological magnetometry: torque on superparamagnetic beads in magnetic fields. PHYSICAL REVIEW LETTERS 2015; 114:218301. [PMID: 26066460 DOI: 10.1103/physrevlett.114.218301] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Indexed: 06/04/2023]
Abstract
Superparamagnetic beads are widely used in biochemistry and single-molecule biophysics, but the nature of the anisotropy that enables the application of torques remains controversial. To quantitatively investigate the torques experienced by superparamagnetic particles, we use a biological motor to rotate beads in a magnetic field and demonstrate that the underlying potential is π periodic. In addition, we tether a bead to a single DNA molecule and show that the angular trap stiffness increases nonlinearly with magnetic field strength. Our results indicate that the superparamagnetic beads' anisotropy derives from a nonuniform intrabead distribution of superparamagnetic nanoparticles.
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Affiliation(s)
- Maarten M van Oene
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - Laura E Dickinson
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - Francesco Pedaci
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Department of Single-Molecule Biophysics, Centre de Biochimie Structurale, UMR 5048 CNRS, Montpellier, France
| | - Mariana Köber
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - David Dulin
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
| | - Jan Lipfert
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
- Department of Physics, Nanosystems Initiative Munich, and Center for NanoScience, Ludwig-Maximilian-University, Amalienstrasse 54, 80799 Munich, Germany
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, Netherlands
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Dulin D, Vilfan ID, Berghuis BA, Hage S, Bamford DH, Poranen MM, Depken M, Dekker NH. Elongation-Competent Pauses Govern the Fidelity of a Viral RNA-Dependent RNA Polymerase. Cell Rep 2015; 10:983-992. [PMID: 25683720 DOI: 10.1016/j.celrep.2015.01.031] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 12/23/2014] [Accepted: 01/10/2015] [Indexed: 02/06/2023] Open
Abstract
RNA viruses have specific mutation rates that balance the conflicting needs of an evolutionary response to host antiviral defenses and avoidance of the error catastrophe. While most mutations are known to originate in replication errors, difficulties of capturing the underlying dynamics have left the mechanochemical basis of viral mutagenesis unresolved. Here, we use multiplexed magnetic tweezers to investigate error incorporation by the bacteriophage Φ6 RNA-dependent RNA polymerase. We extract large datasets fingerprinting real-time polymerase dynamics over four magnitudes in time, in the presence of nucleotide analogs, and under varying NTP and divalent cation concentrations and fork stability. Quantitative analysis reveals a new pause state that modulates polymerase fidelity and so ties viral polymerase pausing to the biological function of optimizing virulence. Adjusting the frequency of such pauses offers a target for therapeutics and may also reflect an evolutionary strategy for virus populations to track the gradual evolution of their hosts.
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Affiliation(s)
- David Dulin
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, the Netherlands
| | - Igor D Vilfan
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, the Netherlands
| | - Bojk A Berghuis
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, the Netherlands
| | - Susanne Hage
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, the Netherlands
| | - Dennis H Bamford
- Department of Biosciences, University of Helsinki, Viikki Biocenter 2, P.O. Box 56 (Viikinkaari 5), 00014 Helsinki, Finland; Institute of Biotechnology, University of Helsinki, Viikki Biocenter 2, P.O. Box 56 (Viikinkaari 5), 00014 Helsinki, Finland
| | - Minna M Poranen
- Department of Biosciences, University of Helsinki, Viikki Biocenter 2, P.O. Box 56 (Viikinkaari 5), 00014 Helsinki, Finland.
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, the Netherlands.
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, the Netherlands.
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44
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Greenfeld M, van de Meent JW, Pavlichin DS, Mabuchi H, Wiggins CH, Gonzalez RL, Herschlag D. Single-molecule dataset (SMD): a generalized storage format for raw and processed single-molecule data. BMC Bioinformatics 2015; 16:3. [PMID: 25591752 PMCID: PMC4384321 DOI: 10.1186/s12859-014-0429-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Accepted: 12/11/2014] [Indexed: 12/15/2022] Open
Abstract
Background Single-molecule techniques have emerged as incisive approaches for addressing a wide range of questions arising in contemporary biological research [Trends Biochem Sci 38:30–37, 2013; Nat Rev Genet 14:9–22, 2013; Curr Opin Struct Biol 2014, 28C:112–121; Annu Rev Biophys 43:19–39, 2014]. The analysis and interpretation of raw single-molecule data benefits greatly from the ongoing development of sophisticated statistical analysis tools that enable accurate inference at the low signal-to-noise ratios frequently associated with these measurements. While a number of groups have released analysis toolkits as open source software [J Phys Chem B 114:5386–5403, 2010; Biophys J 79:1915–1927, 2000; Biophys J 91:1941–1951, 2006; Biophys J 79:1928–1944, 2000; Biophys J 86:4015–4029, 2004; Biophys J 97:3196–3205, 2009; PLoS One 7:e30024, 2012; BMC Bioinformatics 288 11(8):S2, 2010; Biophys J 106:1327–1337, 2014; Proc Int Conf Mach Learn 28:361–369, 2013], it remains difficult to compare analysis for experiments performed in different labs due to a lack of standardization. Results Here we propose a standardized single-molecule dataset (SMD) file format. SMD is designed to accommodate a wide variety of computer programming languages, single-molecule techniques, and analysis strategies. To facilitate adoption of this format we have made two existing data analysis packages that are used for single-molecule analysis compatible with this format. Conclusion Adoption of a common, standard data file format for sharing raw single-molecule data and analysis outcomes is a critical step for the emerging and powerful single-molecule field, which will benefit both sophisticated users and non-specialists by allowing standardized, transparent, and reproducible analysis practices. Electronic supplementary material The online version of this article (doi:10.1186/s12859-014-0429-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Max Greenfeld
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA. .,Department of Biochemistry, Stanford University, Stanford, CA, 94305, USA.
| | | | | | - Hideo Mabuchi
- Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA.
| | - Chris H Wiggins
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, 10027, USA.
| | - Ruben L Gonzalez
- Department of Chemistry, Columbia University, New York, NY, 10027, USA.
| | - Daniel Herschlag
- Department of Chemical Engineering, Stanford University, Stanford, CA, 94305, USA. .,Department of Biochemistry, Stanford University, Stanford, CA, 94305, USA. .,Department of Biochemistry, B400, Stanford University, Stanford, CA, 94305, USA.
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45
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Camera-based three-dimensional real-time particle tracking at kHz rates and Ångström accuracy. Nat Commun 2015; 6:5885. [PMID: 25565216 PMCID: PMC4338538 DOI: 10.1038/ncomms6885] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 11/18/2014] [Indexed: 01/30/2023] Open
Abstract
Optical and magnetic tweezers are widely employed to probe the mechanics and activity of individual biomolecular complexes. They rely on micrometer-sized particles to detect molecular conformational changes from the particle position. Real-time particle tracking with Ångström accuracy has so far been only achieved using laser detection through photodiodes. Here we demonstrate that camera-based imaging can provide a similar performance for all three dimensions. Particle imaging at kHz rates is combined with real-time data processing being accelerated by a graphics processing unit. For particles that are fixed in the sample cell we can detect 3 Å sized steps that are introduced by cell translations at rates of 10 Hz, while for DNA-tethered particles 5 Å steps at 1 Hz can be resolved. Moreover, 20 particles can be tracked in parallel with comparable accuracy. Our approach provides a simple and robust way for high-resolution tweezers experiments using multiple particles at a time.
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46
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Perez-Gonzalez DC, Penedo JC. Single-Molecule Strategies for DNA and RNA Diagnostics. RNA TECHNOLOGIES 2015. [DOI: 10.1007/978-3-319-17305-4_15] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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47
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Lipfert J, van Oene MM, Lee M, Pedaci F, Dekker NH. Torque spectroscopy for the study of rotary motion in biological systems. Chem Rev 2014; 115:1449-74. [PMID: 25541648 DOI: 10.1021/cr500119k] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Jan Lipfert
- Department of Physics, Nanosystems Initiative Munich, and Center for NanoScience (CeNS), Ludwig-Maximilian-University Munich , Amalienstrasse 54, 80799 Munich, Germany
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Slow unloading leads to DNA-bound β2-sliding clamp accumulation in live Escherichia coli cells. Nat Commun 2014; 5:5820. [PMID: 25520215 PMCID: PMC4284645 DOI: 10.1038/ncomms6820] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 11/11/2014] [Indexed: 11/26/2022] Open
Abstract
The ubiquitous sliding clamp facilitates processivity of the replicative polymerase and acts as a platform to recruit proteins involved in replication, recombination and repair. While the dynamics of the E. coli β2-sliding clamp have been characterized in vitro, its in vivo stoichiometry and dynamics remain unclear. To probe both β2-clamp dynamics and stoichiometry in live E. coli cells, we use custom-built microfluidics in combination with single-molecule fluorescence microscopy and photoactivated fluorescence microscopy. We quantify the recruitment, binding and turnover of β2-sliding clamps on DNA during replication. These quantitative in vivo results demonstrate that numerous β2-clamps in E. coli remain on the DNA behind the replication fork for a protracted period of time, allowing them to form a docking platform for other enzymes involved in DNA metabolism. DNA replication is accomplished by the replisome, a multi-protein complex that comprises the sliding clamp. Here, Moolman et al. present quantitative and dynamic measurements of the number of β2-sliding clamps at the single-cell level in live E. coli cells to shed light on key aspects of DNA replication.
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49
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Yu Z, Dulin D, Cnossen J, Köber M, van Oene MM, Ordu O, Berghuis BA, Hensgens T, Lipfert J, Dekker NH. A force calibration standard for magnetic tweezers. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2014; 85:123114. [PMID: 25554279 DOI: 10.1063/1.4904148] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
To study the behavior of biological macromolecules and enzymatic reactions under force, advances in single-molecule force spectroscopy have proven instrumental. Magnetic tweezers form one of the most powerful of these techniques, due to their overall simplicity, non-invasive character, potential for high throughput measurements, and large force range. Drawbacks of magnetic tweezers, however, are that accurate determination of the applied forces can be challenging for short biomolecules at high forces and very time-consuming for long tethers at low forces below ∼1 piconewton. Here, we address these drawbacks by presenting a calibration standard for magnetic tweezers consisting of measured forces for four magnet configurations. Each such configuration is calibrated for two commonly employed commercially available magnetic microspheres. We calculate forces in both time and spectral domains by analyzing bead fluctuations. The resulting calibration curves, validated through the use of different algorithms that yield close agreement in their determination of the applied forces, span a range from 100 piconewtons down to tens of femtonewtons. These generalized force calibrations will serve as a convenient resource for magnetic tweezers users and diminish variations between different experimental configurations or laboratories.
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Affiliation(s)
- Zhongbo Yu
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - David Dulin
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Jelmer Cnossen
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Mariana Köber
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Maarten M van Oene
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Orkide Ordu
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Bojk A Berghuis
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Toivo Hensgens
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Jan Lipfert
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
| | - Nynke H Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands
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50
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Tuson HH, Biteen JS. Unveiling the inner workings of live bacteria using super-resolution microscopy. Anal Chem 2014; 87:42-63. [PMID: 25380480 DOI: 10.1021/ac5041346] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Hannah H Tuson
- Department of Chemistry, University of Michigan , Ann Arbor, Michigan 48109, United States
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